Textbook-Integrated Guide to Educational Resources

TIGER

Manual Data Processing in Analytical Chemistry: Linear CalibrationDora MelucciMost science students are familiar with Excel spreadsheets, but determining which of Excels statistical functions perform a calculation equivalent to a classical equation and calculating errors with Excel are not trivial exercises.Melucci, Dora. J. Chem. Educ.2008, 85, 1346.

Calibration |

Chemometrics |

Quantitative Analysis

Helping Students Assess the Relative Importance of Different Intermolecular InteractionsPaul G. JasienA semi-quantitative model has been developed to estimate the relative effects of dispersion, dipoledipole interactions, and H-bonding on the normal boiling points for a series of simple, straight-chain organic compounds. Application of this model may be useful in addressing student misconceptions related to the additivity of intermolecular interactions.Jasien, Paul G. J. Chem. Educ.2008, 85, 1222.

Teaching Mathematics to Chemistry Students with Symbolic ComputationJ. F. Ogilvie and M. B. MonaganThe authors explain how the use of mathematical software improves the teaching and understanding of mathematics to and by chemistry students while greatly expanding their abilities to solve realistic chemical problems.Ogilvie, J. F.; Monagan, M. B. J. Chem. Educ.2007, 84, 889.

Cross-Proportions: A Conceptual Method for Developing Quantitative Problem-Solving SkillsElzbieta Cook and Robert L. CookThis paper focuses attention on the cross-proportion (C-P) method of mathematical problem solving, which was once widely used in chemical calculations. We propose that this method regain currency as an alternative to the dimensional analysis (DA) method, particularly in lower-level chemistry courses. In recent years, the DA method has emerged as the only problem solving mechanism offered to high-school and general chemistry students in contemporary textbooks, replacing more conceptual methods, C-P included. Cook, Elzbieta; Cook, Robert L. J. Chem. Educ.2005, 82, 1187.

Learning Theories |

Stoichiometry |

Chemometrics |

Student-Centered Learning

The Reaction Quotient Is Unnecessary To Solve Equilibrium ProblemsPaul S. MatsumotoThe traditional method to determine the equilibrium concentration of chemicals in a reaction, given the equilibrium constant and the initial concentration of chemicals in the reaction, involves the determination of the reaction quotient. This article will demonstrate that this step may be eliminated; thereby simplifying the algorithm to solve such problems. Such a reduction in the complexity of the algorithm may result in more students successfully being able to solve such problems. Matsumoto, Paul S. J. Chem. Educ.2005, 82, 406.

Equilibrium |

Learning Theories |

Chemometrics

Capillary Electrophoresis Analysis of Cations in Water Samples. An Experiment for the Introductory LaboratoryChristopher J. Pursell, Bert Chandler, and Michelle M. BusheyThis experiment can be done in a lab, as a "dry-lab", or as an in-class exercise. Students explore a number of basic separation topics and work with figures of merit for real and meaningful samples. We have adopted a strategy where students encounter various instruments and methods of analyses multiple times throughout the curriculum. The level of sophistication in the exposures increases with the experience level of the students. Through this repeated exposure students will gain a better and fuller understanding of these methods than they would with a single exposure to the technique in the analytical or instrumental laboratory. Pursell, Christopher J.; Chandler, Bert; Bushey, Michelle M. J. Chem. Educ.2004, 81, 1783.

Electrophoresis |

Quantitative Analysis |

Separation Science |

Chemometrics |

Water / Water Chemistry

Statistical Comparison of Data in the Analytical LaboratoryMichael J. SamideIn this article, an experiment designed to provide students with an experience involving statistical treatment of data is described. This experiment allows students to compare 11 different techniques for measuring specific volumes of water. Replicate measurements are taken for each technique and comparisons are made both within a data set and between different data sets. Through calculation of t-values, students are able to draw conclusions about the precision and accuracy of these various techniques.Samide, Michael J. J. Chem. Educ.2004, 81, 1641.

Chemometrics

Unified Approximations: A New Approach for Monoprotic Weak Acid–Base EquilibriaHarry L. Pardue, Ihab N. Odeh, and Teweldemedhin M. TesfaiThis article describes a new approach to approximate calculations for monoprotic acidbase equilibria in otherwise pure water. The new approach, identified herein as unified approximations, uses a simple decision criterion to select between situations that should be treated as deprotonation and protonation reactions. The remaining treatment takes account of changes in concentrations of conjugate acidbase pairs for all situations and ignores autoprotolysis only for situations for which the analytical concentration of either the conjugate acid or conjugate base will always be larger than zero. Pardue, Harry L.; Odeh, Ihab N.; Tesfai, Teweldemedhin M. J. Chem. Educ.2004, 81, 1367.

Acids / Bases |

Equilibrium |

Chemometrics

Reaction to Why Do We Teach Equilibrium Calculations?Stephen J. Hawkes"Rigor" in introductory chemistry is often equated with quantitation. Consequently the understanding of chemical reactions and properties is obscured. This was illustrated by Stumpo who asked students to calculate ?E of a reaction, and then on another question on the same test asked a question aimed at its meaning. 77% of the students calculated correctly, but only 24% showed understanding of its meaning. The ability to calculate a number does not measure understanding of the number. Hawkes, Stephen J. J. Chem. Educ.2004, 81, 1265.

Equilibrium |

Chemometrics

Reaction to Why Do We Teach Equilibrium Calculations? Don L. LewisA recently published correspondence by Stephen J. Hawkes on teaching equilibrium calculations troubles me. Hawkes dismisses equilibrium calculations as mere algorithms, best deferred until the student can use computer programs. I find it difficult to believe that a computer program enhances understanding. From a chemists point of view, the equilibrium condition is a limit, a limit that (because of stochastic considerations) does not exist. It might be better to make the reaction quotient statement using < or > but the use of those relations is delayed until quantum mechanics.Lewis, Don L. J. Chem. Educ.2004, 81, 1265.

Equilibrium |

Chemometrics

Using a Graphing Calculator To Determine a First-Order Rate Constant: Author ReplyJosé E. Cortés-FigueroaWhen technology is used to help with mathematical calculations, the emphasis must be on the concepts being learned rather than simply the procedures. In our approach we are attempting to help students learn more about the concept and also to attain data analysis skills they will need in the future. Cortés-Figueroa, José E. J. Chem. Educ.2004, 81, 485.

SpecScan: A Utility Program for Generating Numerical Data from Printed Forms of Spectra or Other SignalsConstantinos E. EfstathiouSpecSpan is a utility program for Microsoft Windows that generates numerical data from printed spectra or other plots found as figures in text, chart recordings, or freehand drawings. SpecScan can process bitmap (.BMP) images of such figures and drawings. After a brief interaction with the user, it generates and exports numerical data as Excel (.XLS) or text (.TXT) files.Efstathiou, Constantinos E. J. Chem. Educ.2003, 80, 1093.

Two Linear Correlation CoefficientsRobert de LevieIn fitting data to a straight line, many calculators and computer programs display a linear correlation coefficient. Two types of linear correlation coefficients are discussed, one often useful in chemical calculations, the other usually not. de Levie, Robert. J. Chem. Educ.2003, 80, 1030.

What's Been Happening to Undergraduate MathematicsDavid M. BressoudAn overview of some of the changes that have been occurring in undergraduate mathematics education; based on a workshop held by the Mathematical Association of America to determine what chemists expect their students to learn from undergraduate mathematics courses in terms of understanding, content, and use of technology. Bressoud, David M. J. Chem. Educ.2001, 78, 578.

Learning Theories |

Mathematics / Symbolic Mathematics |

Chemometrics

Understanding Solubility through Excel SpreadsheetsPamela BrownThis article describes assignments related to the solubility of inorganic salts that can be given in an introductory general chemistry course. These assignments address the need for math, graphing, and computer skills in the chemical technology program by developing skill in the use of Microsoft Excel to prepare spreadsheets and graphs and to perform linear and nonlinear curve-fitting. Brown, Pamela. J. Chem. Educ.2001, 78, 268.

Aqueous Solution Chemistry |

Chemometrics |

Precipitation / Solubility

A Simple Laboratory Experiment for the Determination of Absolute ZeroMyung-Hoon Kim, Michelle Song Kim, and Suw-Young LyA novel method that employs a remarkably simple and inexpensive apparatus and is based on the extrapolation of the volume of a given amount of dry air to zero volume after a volume of air trapped inside a 10-mL graduated cylinder is measured at various temperatures.Kim, Myung-Hoon; Kim, Michelle Song; Ly, Suw-Young. J. Chem. Educ.2001, 78, 238.

Pixel Conversion: A Simple Way to Extract Coordinates of Points from a Printed GraphChristian Aymard and Randall B. ShirtsA very simple method is described for extracting the coordinates of points from printed graphs, student reports, or publications. One only needs a flatbed scanner and a desktop computer. This is a convenient and inexpensive alternative to the tedious traditional method using a ruler or to the more costly programs available commercially. A Windows program has been made available to perform the required operations. Aymard, Christian; Shirts, Randall B. J. Chem. Educ.2000, 77, 1230.

Chemometrics

Encouraging Meaningful Quantitative Problem SolvingJeff Cohen, Meghan Kennedy-Justice, Sunny Pai, Carmen Torres, Rick Toomey, Ed DePierro, and Fred GarafaloThis paper describes the efforts of a group of teachers to help college freshman chemistry students and high school science students to improve their problem-solving skills. The presentation includes several sets of questions intended to elucidate ideas and to involve the reader in the process of reflecting upon his or her own problem-solving strategies. Cohen, Jeff; Kennedy-Justice, Meghan; Pai, Sunny; Torres, Carmen; Toomey, Rick; DePierro, Ed; Garafalo, Fred. J. Chem. Educ.2000, 77, 1166.

Mathematics / Symbolic Mathematics |

Chemometrics

A Classroom Exercise in Sampling TechniqueMichael R. RossA classroom hands-on demonstration has been developed that looks at the two important sampling considerations, sample size and non-homogeneous sample materials. This classroom activity makes use of readily available M&M candies for the sample size and NERDS for the non-homogeneous sample exercises. Ross, Michael R. J. Chem. Educ.2000, 77, 1015.

Predicting Acid-Base Titration Curves without CalculationsDennis W. BarnumIn this paper a qualitative and systematic method for sketching titration curves is presented. Even the more complex cases such as salts or polyprotic acids and bases are treated just as easily as simple monoprotic acids. Having students predict the shape of titration curves from known equilibrium constants helps to focus attention on the general principles without distraction by the mathematics. Barnum, Dennis W. J. Chem. Educ.1999, 76, 938.

Acids / Bases |

Quantitative Analysis |

Water / Water Chemistry |

Equilibrium |

Learning Theories |

Titration / Volumetric Analysis |

Chemometrics

Do pH in Your HeadAddison AultEvery aqueous solution has a pH. Two factors determine this pH: the acidic or basic strength of the solute, and its concentration. When you use pKa values to express acidic and basic strength you can easily estimate the approximate pH of many aqueous solutions of acids, bases, and their salts and their buffers.Ault, Addison. J. Chem. Educ.1999, 76, 936.

An Easy and Effective Classroom Demonstration of Population DistributionsMarjorie A. JonesUsing a simple experimental design and easily obtained materials, a classroom experiment was conducted to demonstrate normal-distribution behavior for a population. We used popcorn and a hot-air popper. Popped kernels were collected with time and data were plotted as popped kernels per time interval versus time. The data clearly showed a normal (Gaussian) distribution. Jones, Marjorie A. J. Chem. Educ.1999, 76, 384.

Chemometrics

Effect of Sample Size on Sampling Error: An Experiment for Introductory Analytical ChemistryJoseph E. Vitt and Royce C. EngstromStudents acquire samples of various size from a binary population, calculate the relative standard deviations for each sample size, and compare these results with those predicted by the binomial distribution. This experiment gives excellent agreement for the pooled student data, and the results show the expected decrease in sampling error as the sample size increases. Vitt, Joseph E.; Engstrom, Royce C. J. Chem. Educ.1999, 76, 99.

Quantitative Analysis |

Instrumental Methods |

Chemometrics

CHEMiCALC (4000161) and CHEMiCALC Personal Tutor (4001108), Version 4.0 (by O. Bertrand Ramsay)Scott White and George BodnerCHEMiCALC is a thoughtfully designed software package developed for use by high school and general chemistry students, who will benefit from the personal tutor mode that helps to guide them through unit conversion, empirical formula, molecular weight, reaction stoichiometry, and solution stoichiometry calculations.White, Scott; Bodner, George M. J. Chem. Educ.1999, 76, 34.

Modeling Nuclear Decay: A Point of Integration between Chemistry and MathematicsKent J. Crippen and Robert D. CurtrightA four-part activity utilizing a graphing calculator to investigate nuclear stability is described. Knowledge acquired through the activity provides background for answering the societal question of using nuclear materials for energy production. Crippen, Kent J.; Curtright, Robert D. J. Chem. Educ.1998, 75, 1434.

Nuclear / Radiochemistry |

Atomic Properties / Structure |

Chemometrics

There Seems To Be Uncertainty about the Use of Significant Figures in Reporting Uncertainties of ResultsJulio F. Caballero and Delphia F. HarrisA cursory review of two journals indicates that uncertainties in experimental results are not consistently reported in the literature with the correct number of significant figures. The problem seems more frequent in computer generated results in both chemical education and research articles. Examples of published values with uncertainty inappropriately reported are included along with the appropriate rounding. Caballero, Julio F.; Harris, Delphia F. J. Chem. Educ.1998, 75, 996.

Laboratory Equipment / Apparatus |

Learning Theories |

Chemometrics

Precision and Accuracy in Measurements: A Tale of Four Graduated CylindersRichard S. TreptowThe concepts of precision and accuracy help students understand that uncertainty accompanies even our best scientific measurements. A model experiment can be used to distinguish the two terms. The experiment uses four graduated cylinders which give measurements of different accuracy and precision. Such terms as mean, range, standard deviation, error, and true value are defined through an illustration.Treptow, Richard S. J. Chem. Educ.1998, 75, 992.

Percent Composition and Empirical Formula - A New ViewGeorge L. GilbertA new method of obtaining the empirical formula for a compound from its percent composition is proposed. The method involves the determination of a minimum molar mass for the compound based on the percentage of each element, obtaining the lowest common molar mass and using this data to calculate the integer values used in writing the empirical formula. Gilbert, George L. J. Chem. Educ.1998, 75, 851.

Atomic Properties / Structure |

Stoichiometry |

Chemometrics

Production of Numerical Chemical Problems Using a SpreadsheetPeter G. HallThe use of spreadsheets for "personalized" assignments. These assignments take the form of printed chemical problems such that every student has different numerical data. The problem sets make a challenging student introduction to word processing and spreadsheet use. Hall, Peter G. J. Chem. Educ.1998, 75, 243.

Chemometrics

The Chemistry Maths Book (by Erich Steiner) C. Michael McCallumThe Chemistry Maths Book contains all the mathematical methods that 99% of chemists would need. Designed as a text for an actual Maths for Chemists course, it is laid out in a logical progression from simple (decimals, algebra, and functions) to the more complicated but no less important (matrix algebra, differential equations, and matrix eigenvalue problems). It seems well suited both for its stated purpose and as a "brush-up" book for undergraduates, graduate students, and others. McCallum, C. Michael. J. Chem. Educ.1997, 74, 1400.

Chemometrics |

Mathematics / Symbolic Mathematics

A Note on Covariance in Propagation of UncertaintyEdwin F. MeyerIt is pointed out that whenever both the slope and the intercept are used in calculating a physical quantity from a linear regression, propagation of error must include the covariance as well as the variances. The point is illustrated with a calculation of the boiling point of water from the parameters of the lnP vs 1/T fit. If the covariance is omitted from the propagation of error, the estimate of uncertainty is unreasonably large. Meyer, Edwin F. J. Chem. Educ.1997, 74, 1339.

Graham's Law and Perpetuation of ErrorStephen J. HawkesGrahams Laws of effusion and diffusion are used in recent articles for traditional experiments to which they do not in fact apply and for which they give the wrong answer.Hawkes, Stephen J. J. Chem. Educ.1997, 74, 1069.

Gases |

Chemometrics |

Transport Properties

Rounding Numbers: Why the "New System" Doesn't WorkW. Robert MiddenThis paper explains a correction to the rounding rule previously published in this Journal. The earlier article reported that the best way to round numbers is to always round up when the first digit dropped is 5. However, this will lead to accumulation of error when errors are averaged.Midden, W. Robert. J. Chem. Educ.1997, 74, 405.

Chemometrics

Sensitivity to Experimental Parameters via SpreadsheetsB. R. SundheimIn spreadsheet computations wherever the functional dependence of calculated results on experimental quantities is obscure, sensitivities may be obtained by testing the effects of variations in relevant inputs. An example is given where Hess' law is explored calorimetrically.Sundhein, B. R. . J. Chem. Educ.1997, 74, 328.

Chemometrics

Curve Fitting: An Alternative Approach to Analyzing Kinetic Data in Introductory ChemistryColeman, William F.183. The availability of high quality software for performing nonlinear curve fitting on microcomputers allows students to take an alternative approach to data analysis, one that concentrates on functional forms that may be more natural than some of the algebraic machinations necessary to render relationships into linear forms. An example of the application of such an approach to the analysis of kinetic data is presented in this paper.Coleman, William F. J. Chem. Educ.1996, 73, 243.

Chemometrics |

Kinetics

Significant Figures in Graph InterpretationDonald M. GrahamA means is derived for calculating the number of significant figures in the slope and intercept of an experimental linear graph. The method is based on the actual scatter in the points rather than on the nominal precision in the original data, and it can be used even by students who are mathematically fairly unsophisticated. Graham, Donald M. J. Chem. Educ.1996, 73, 211.

Those Baffling SubscriptsArthur W. Friedel and David P. MaloneyStudy of the difficulties students have in interpreting subscripts correctly and distinguishing atoms from molecules when answering questions and solving problems.Friedel, Arthur W.; Maloney, David P. J. Chem. Educ.1995, 72, 899.

Solving equilibria problems with a graphing calculator: A robust method, free of algebra and calculus Ruch, David K.; Chasteen, T. G.The method of successive approximations is frequently introduced in freshman chemistry as a means for solving equilibrium equations. However, this often requires an understanding of calculus that is problematic for introductory chemistry students. An alternative method to solving such equations is to use graphic calculators to solve problems graphically.Ruch, David K.; Chasteen, T. G. J. Chem. Educ.1993, 70, A184.

How thick/thin is your mirror?McCullough, Thomas; Bell, LisaWhen a student reported that his/her water film was 6 cm thick, these authors felt a review of significant figures and dimensional analysis may be in order.McCullough, Thomas; Bell, Lisa J. Chem. Educ.1993, 70, 851.

Chemometrics

Measurement scales: Changing Celsius to Kelvin is not just a unit conversion Nordstrom, Brian H.The key to understanding the difference between Celsius and Kelvin lies in the different types of measurement scales. Students may have an easier time manipulating equations (such as gas laws) if they knew the difference between these scales.Nordstrom, Brian H. J. Chem. Educ.1993, 70, 827.

A mole of M&M's Merlo, Carmela; Turner, Kathleen E.Engaging students by asking the question: How thick would the layer of M&M candies be if we covered the continental United States with a mole of these candies? Compare this to a mole of water.Merlo, Carmela; Turner, Kathleen E. J. Chem. Educ.1993, 70, 453.

Stoichiometry |

Chemometrics

AnswerSheetsCornelius, RichardReview of a spreadsheet-like program that includes modules on significant figures, conversions, stoichiometry, and VSEPR structures.Cornelius, Richard J. Chem. Educ.1993, 70, 387.

Measuring Avogadro's number on the overhead projector Solomon, Sally; Hur, ChinhyuA Petri dish filled with water and stearic acid dissolved in petroleum ether upon an overhead projector can be used to introduce the topic of Avogadro's number.Solomon, Sally; Hur, Chinhyu J. Chem. Educ.1993, 70, 252.

Concept learning versus problem solving: There is a difference Nakhleh, Mary B.; Mitchell, Richard C.Previous studies indicate that there is little connection between algorithmic problem solving skills and conceptual understanding. The authors provide some ways to evaluate students along a continuum of low-high algorithmic and conceptual problem solving skills. The study shows that current lecture method teaches students to solve algorithms rather than teaching chemistry concepts.Nakhleh, Mary B.; Mitchell, Richard C. J. Chem. Educ.1993, 70, 190.

Chemometrics |

Learning Theories |

Student-Centered Learning

An Investigative Density Experiment Samsa, Richard A.A laboratory exercise about density that is engaging and allows students to use higher-level thinking skills and develop a plan to solve a problem.Samsa, Richard A. J. Chem. Educ.1993, 70, 149.

Laboratory Computing / Interfacing |

Chemometrics |

Physical Properties

More on the Question of Significant FiguresClase, Howard J.Because so many students have a hard time understanding what significant figures are all about, this author developed a method using "?" to substitute for insignificant zeros. This helps many students finally grasp this convention.Clase, Howard J. J. Chem. Educ.1993, 70, 133.

Chemometrics

Equilibrium CalculatorAllendoerfer, RobertThe equilibrium calculator can calculate the equilibrium concentrations of all reagents in an arbitrary chemical reaction with as many as five reactants and products.Allendoerfer, Robert J. Chem. Educ.1993, 70, 126.

Is Dimensional Analysis the Best We Have to Offer?Canagaratna, Sebastian G.Dimensional analysis is a unit based approach while the alternative, "method of equations" is a relations-based approach to solving mathematical problems. The author argues that quantitative chemistry involves relationships between quantities and not units, making the later method more pedagogically sound.Canagaratna, Sebastian G. J. Chem. Educ.1993, 70, 40.

On the chemically impossible "other" roots in equilibrium calculations, IILudwig, Oliver G.In a previous paper the author described, using mathematics accessible to students, how an equilibrium calculation leading to a quadratic equation may be shown to have but one "chemical" root. The present work extends this demonstration to some reactions leading to cubic equations.Ludwig, Oliver G. J. Chem. Educ.1992, 69, 884.

Chemical equations are actually matrix equationsAlberty, Robert A.Chemists tend to think that chemical equations are unique to chemistry and they are not used to thinking of chemical equations as the mathematical equations they in fact are. The objective of this paper is to illustrate the mathematical significance of chemical equations.Alberty, Robert A. J. Chem. Educ.1991, 68, 984.

Stoichiometry |

Chemometrics

KC? Discoverer: Exploring the properties of the chemical elementsLiebel, MichaelThis software program allows users to explore a large number of properties of the elements. The program can find all elements associated with a certain property, graph numeric properties against other numeric properties, list elements, sort elements, and use the periodic table to select elements.Liebel, Michael J. Chem. Educ.1991, 68, 956.

Chemical equilibrium: III. A few math tricks Gordus, Adon A.The third article in a series on chemical equilibrium that considers a few math "tricks" useful in equilibrium calculations and approximations.Gordus, Adon A. J. Chem. Educ.1991, 68, 291.

Finding largest common factors and simplest integer ratios Macomber, Roger S.General chemistry students can ease some of their math-phobia with an exam question that deals with a familiar topic prior to putting these same mathematical principles into the context of chemistry.Macomber, Roger S. J. Chem. Educ.1991, 68, 42.

Accuracy of measurements and the U.S. CensusGorin, GeorgeSome aspects of taking the Census can help students to understand the problem of measurement error and the use of significant figures.Gorin, George J. Chem. Educ.1990, 67, 936.

ChemCalc: A scientific calculatorAllendoerfer, Robert D.A scientific calculator program that can be used as a stand-alone or incorporated into other software written in BASIC.Allendoerfer, Robert D. J. Chem. Educ.1990, 67, 770.

Dynamic data storage in FORTRANChung-Phillips, Alice115. Bits and pieces, 44. The purpose of this article is to promote the use of dynamic storage allocation in FORTRAN to chemistry instructors and students in the present computing environment.Chung-Phillips, Alice J. Chem. Educ.1990, 67, 500.

Accurate equations of state in computational chemistry projectsAllbee, David; Jones, Edward101. This article presents one method that allows students to become familiar with the use of modern equations of state and also enhances their understanding of how computers can be used in the study and application of chemistry. [Includes "Editor's note: Changes in the computer series", by Lagowski, J. J., p. 226]Allbee, David; Jones, Edward J. Chem. Educ.1989, 66, 226.

Analysis of kinetic data with a spreadsheet programHenderson, JohnAn article about spreadsheet templates that accept concentration versus time data for several runs of an experiment, determination of least-squares lines through data points for each run, and will allow the user to exclude points from the least-squares calculation.Henderson, John J. Chem. Educ.1988, 65, A150.

Let's separate theories from calculations Freilich, Mark B.This author writes in a 'provocative opinion' article challenging the readers to think about heavily emphasizing 'thought problems' in chemistry and allowing students to master those before throwing calculations into the mix.Freilich, Mark B. J. Chem. Educ.1988, 65, 442.

Chemometrics

An alternative to using the PV = nRT equation Desmarais, GeorgeThis author shares his application of the factor-label method to solving gas problems which involves using the ideal gas constant as the starting point in the relationship.Desmarais, George J. Chem. Educ.1988, 65, 392.

Good numerical technique in chemistry: The quadratic equationThompson, H. BradfordTexts commonly avoid examples with bad round-off problems or handle them by approximation; none of this is necessary, for simple techniques are available to handle quadratic equations easily and precisely.Thompson, H. Bradford J. Chem. Educ.1987, 64, 1009.

Mole fraction revisitedMancott, A.This problem requires the use of algebraic reasoning to derive and solve a fraction linear equation based on the concept of moles and conservation of moles.Mancott, A. J. Chem. Educ.1987, 64, 320.

The length of a pestle: A class exercise in measurement and statistical analysisO'Reilly, James E.Too many students get through chemistry without acquiring a basic understanding and appreciation of the concepts of measurement science. The purpose of this report is to outline an extremely simple class exercise as a concrete paradigm of the entire process of making chemical measurements and treating data.O'Reilly, James E. J. Chem. Educ.1986, 63, 894.

Where did that number come from? DeLorenzo, RonaldWith more careful labeling and handling of numbers, instructors can reduce the confusion students sometimes feel when watching problems being solved by the instructor on the board.DeLorenzo, Ronald J. Chem. Educ.1986, 63, 514.

Mathematics in the chemistry classroom. Part 2. Elementary entities play their partDierks, Werner; Weninger, Johann; Herron, J. DudleyOne of the problems that learners have to overcome when doing stoichiometry calculations is to learn how statements about elementary entities given by formulas and equations are related to statements about portions of substances as measured in the macroscopic world.Dierks, Werner; Weninger, Johann; Herron, J. Dudley J. Chem. Educ.1985, 62, 1021.

A LAP on moles: Teaching an important conceptIhde, JohnThe objective of the Learning Activity Packet on moles include understanding the basic concept of the mole as a chemical unit, knowing the relationships between the mole and the atomic weights in the periodic table, and being able to solve basic conversion problems involving grams, moles, atoms, and molecules. [Debut]Ihde, John J. Chem. Educ.1985, 62, 58.

The factor-label method: Is it all that great?Navidi, Marjorie H.; Baker, A. DavidThe development of reasoning skills in chemistry is better achieved by postponing the introduction of the factor-label method.Navidi, Marjorie H.; Baker, A. David J. Chem. Educ.1984, 61, 522.

Reflections upon mathematics in the introductory chemistry courseGoodstein, Madeline P.It is the purpose of this paper to call attention to the lack of mathematical competence by chemistry students and to invite consideration of one conceptual scheme which may be used to unify the mathematical approach.Goodstein, Madeline P. J. Chem. Educ.1983, 60, 665.

Chemometrics |

Gases

On the chemically impossible "other" roots in equilibrium problemsLudwig, Oliver G.Students often have a hard time knowing when to disregard equilibrium roots that are too large or are negative. The author suggests a convincing proof that helps students understand how the relationship between the conceptual and mathematical.Ludwig, Oliver G. J. Chem. Educ.1983, 60, 547.

Equilibrium |

Chemometrics

Empirical pKb and pKa for nonmetal hydrides from periodic table positionBayless, Philip L.The equation in this article was developed by the author. It estimates the aqueous pKa for certain acids to an average deviation of 0.1pK unit for those with experimentally determined values and agrees with experimentally determined values, and as well as with estimates for those too weak or too strong to be measured.Bayless, Philip L. J. Chem. Educ.1983, 60, 546.

Acids / Bases |

pH |

Chemometrics

Le Châtelier's principle: the effect of temperature on the solubility of solids in liquidsBrice, L. K.The purpose of this article is to provide a rigorous but straightforward thermodynamic treatment of the temperature dependence of solubility of solids in liquids that is suitable for presentation at the undergraduate level. The present discussion may suggest how to approach the qualitative aspects of the subject for freshman.Brice, L. K. J. Chem. Educ.1983, 60, 387.

Mass spectral analysis of halogen compounds Holdsworth, David K.37. Bits and pieces, 14. A pocket calculator can be programmed to decide and display the halogen combination in a molecular-ion cluster by examination of the (M+2)/M or (X+2)/X percentage values.Holdsworth, David K. J. Chem. Educ.1983, 60, 103.

Mathematics in data analysis: An introductionWang, TaitzerThe meaning of simple mathematical equations are described in a perspective that, for some reasons, many beginning students do not seem to be able to obtain from reading textbooks on the subject.Wang, Taitzer J. Chem. Educ.1982, 59, 592.

Think Wheeler, S. J., James D.Students have an easy enough time crunching numbers, but it is alarming how little they understand the concepts behind the numbers. Students should not be making remarks such as, "If they keep changing how they write the problems, how am I supposed to know how to solve them?"Wheeler, S. J., James D. J. Chem. Educ.1981, 58, 1004.

Learning Theories |

Chemometrics

Small things and large numbers Rosenberg, Milton H.Some challenging solubility problems are featured in this note.Rosenberg, Milton H. J. Chem. Educ.1981, 58, 962.

Pressure and the exploding beverage container Perkins, Robert R.The question in this article is an extension of exploding pop bottles to illustrate the balancing of a chemical equation, enthalpy, stoichiometry, and vapor pressure calculations, and the use of the Ideal Gas Equation. The question is aimed at the first-year level student.Perkins, Robert R. J. Chem. Educ.1981, 58, 363.

Empirical formulas - A ratio problemKnox, KerroA problem involving an analogy between ratios of boys to girls given their average weights and percentage composition of the class by weight.Knox, Kerro J. Chem. Educ.1980, 57, 879.

Intuitive and general approach to acid-base equilibrium calculationsFelty, Wayne L.The purpose of this paper is to show that the usual intuitive approach used in general chemistry can be readily extended without introduction of additional, sophisticated concepts to give the general, exact expression and to point out the pedagogical advantage of its use.Felty, Wayne L. J. Chem. Educ.1978, 55, 576.

Acids / Bases |

Equilibrium |

Chemometrics

Pressure calculations Schultz, Charles W.This question requires students to be able to distinguish two kinds of pressure: Boyles law pressure of gas (that depends on volume) from the equilibrium vapor pressure above a liquid (that does not).Schultz, Charles W. J. Chem. Educ.1978, 55, 515.

Teaching the method of successive approximationsNassiff, Peter J.; Boyko, E. R.The purpose of this papers is to help the teacher show the student why basic methods of successive approximations work, how they may be applied, and under what conditions it will be successful.Nassiff, Peter J.; Boyko, E. R. J. Chem. Educ.1978, 55, 376.

The chemical equation. Part I: Simple reactionsKolb, DorisA chemical equation is often misunderstood by students as an "equation" that is used in chemistry. However, a more accurate description is that it is a concise statement describing a chemical reaction expressed in chemical symbolism.Kolb, Doris J. Chem. Educ.1978, 55, 184.

Cookbook dimensional analysisDeLorenzo, RonaldFrequently, teachers will hear, "...it looks easy when you do it..." when teaching dimensional analysis. This teacher advises others on a way to help students gain self-efficacy with this problem solving-strategy.DeLorenzo, Ronald J. Chem. Educ.1976, 53, 633.

Maximizing profits in equilibrium processesRish, Ronald J.Provides the student with an example in which both chemical principles and calculus are applied to a realistic industrial situation where profits are a must.Rish, Ronald J. J. Chem. Educ.1975, 52, 441.

Equilibrium |

Industrial Chemistry |

Chemometrics

Molar solubility calculations and the control equilibriumChaston, S. H. H.The Control-Equilibrium method uses as its starting point a precise procedure for obtaining the equilibrium that accounts for the bulk of the decomposition of starting materials.Chaston, S. H. H. J. Chem. Educ.1975, 52, 206.

Using alligation alternate to solve composition problemsMancott, AnatolProblems involving the composition of mixtures may be solved by using the relatively obscure method of "alligation alternate" in lieu of the standard algebraic procedure with no loss in accuracy; includes five examples.Mancott, Anatol J. Chem. Educ.1972, 49, 57.

SI units in physico-chemical calculationsNorris, A. C.This article demonstrates how the adoption of SI units affects some of the more important physico-chemical calculations found at the undergraduate level.Norris, A. C. J. Chem. Educ.1971, 48, 797.

Hydrolysis of sodium carbonateNakayama, F. S.Presents a procedure for obtaining the ion concentrations of the various component species produced by the hydrolysis of sodium carbonate.Nakayama, F. S. J. Chem. Educ.1970, 47, 67.

Teaching ionic equilibrium: Use of log chart transparenciesFreiser, Henry; Fernando, QuintusThe use of graphical methods brings the problem of significance of various terms in complicated expressions into proper focus. Furthermore, a pictorial representation permits the student to see at a glance how the concentrations of various species in a system at equilibrium change with conditions.Freiser, Henry; Fernando, Quintus J. Chem. Educ.1965, 42, 35.

The Carnot cycle and Maxwell's relationsNash, Leonard K.Maxwells equations can be derived from nothing more than the Carnot cycle and the deployment of the simplest plane geometry.Nash, Leonard K. J. Chem. Educ.1964, 41, 368.

Thermodynamics |

Chemometrics

Beer's law without calculusPinkerton, Richard C.There is no good reason for using calculus in the presentation of Beer's law.Pinkerton, Richard C. J. Chem. Educ.1964, 41, 366.

A simple method for finding slopesHoare, James P.Describes a simple method for determining the tangent at any point on a given curve using a solid glass rod.Hoare, James P. J. Chem. Educ.1961, 38, 570.

Chemometrics

An approach to complex equilibrium problemsButler, James N.Presents an approach to equilibrium problems that sets up enough equations relating the various concentrations present to define the system completely and then makes approximations that simplify the equations.Butler, James N. J. Chem. Educ.1961, 38, 141.

An exact titration equationBolie, Victor W.The purpose of this paper is to show the development of a titration equation for a precipitation reaction which is exact in the mathematical sense.Bolie, Victor W. J. Chem. Educ.1958, 35, 449.